Known in the art is a so-called wafer level packaged acoustic wave device (for example Patent Literature 1). The acoustic wave device in Patent Literature 1 has an element substrate which is comprised of a piezoelectric member, excitation electrodes which provided on a major surface of the element substrate, a cover which covers the excitation electrodes, and terminals which are connected to the excitation electrodes and are exposed from an upper surface of the cover. The acoustic wave device is placed to make a top surface of the cover face a mounting surface of a mounting board, then the terminals are connected by solder with the pads of the mounting surface. Next, the acoustic wave device is covered by a sealing resin whereby it is sealed.